Really nice game with awesome graphics and music!
It is very easy to play though (because you can't die and there are no real obstacles ( you can just leave your mouse behind the penguin and he will be moving, so the rock didn't really do anything)
Maybe some walls or even tunnels could be added (I could imagine a very rich background design under a glacier) You could also go into the educational niche and make it a game about how climate change effects penguins and ice (with a storyline that could potentially be heartbreaking)
Really enjoyed playing! Hope you develop this idea further! :D